Bulb grading machine



ApriI ZO, 1943.

V. L. PARKER BULB GRADING MACHINE Filed Jan. 30, 1940 INVENTOR.

' Vicfor L Pa BY ATTORNEY.

Patented Apr. 20, 1943 UNITED STATES PATENT OFFICE BULB GRADING MACHINE Victor Lee Parker, Cedar Falls, Wash.

Application January 30, 1940, Serial No. 316,362

2 Claims.

The present invention relates to an improvement in bulb grading machine, and more in particular to the construction of the openings, or perforations, through which the bulbs of a particular size pass from the ungraded mass to a graded portion thereof.

In the grading of bulbs which have flattened ellipsoidal shapes, for example, iris bulbs, it has been impossible in the past to devise a machine which would grade them uniformly according to the value, or size, of the maximum diameter along their minor axis. If an ordinary perforated drum were used the major axis of the bulb would lie across the opening and the bulb would carry across. If slats were used the grading would be on the basis of the minimum diameter of the minor axis. Applicants present invention remedies these defects.

It is an object of the present invention to devise a grader for iris or other ellipsoidal objects which will give a uniform grade, and which will remedy the defects of the prior art as noted above.

It is another object of the present invention to devise a grader for soft and delicate objects such as bulbs which will not bruise the objects during the grading.

It is another object of the invention to reduce the length of travel and the amount of handling to which soft and delicate objects such as bulbs are subjected during a grading operation.

These objects and others which will be apparent from the description and claims herewith have been attained by constructing a revolving drum and providing it with perforated walls. The perforations of the walls taper in the direction of travel therethrough of the objects to be graded. The construction of the openings causes an ellipsoidal object to be orientated with its major axis coincident with the axis of the opening and prevents the major axis from lying across the opening as it would be likely to do if the opening were cylindrical or tapered outwardly. Any objects that become lodged in an opening are removed therefrom by means of a toothed wheel, each tooth of which enters an opening as the drum and wheel revolve. This wheel is placed outside of and near the lower side of the inclined drum. This dislodges the bulbs at a place where they will not fal1 through space but will gently roll down the inside of the drum. The inside of the drum and the openings may be coated with a film of rubber or other suitable resilient material. Also, the edges of the openings are rounded to prevent injury to the bulbs.

In the accompanying drawing there is illustrated a device for accomplishing the above objects and constructed in accordance with the above outline. In the drawing:

Figure 1 is an elevational view of an arrangement of drums involving the present invention.

Figure 2 is a section on the line 2-2 of Figure 1 showing some of the details of construction.

Figure 3 is an enlargement of a portion of Figure 2 along the line 3--3.

In Figure 1 the drum l is arranged in a nearly horizontal position, within three or four degrees, and is mounted for rotation and is rotated by any suitable means. Bulbs are fed down the chute 2 and into the high end of the drum. The walls of thedrum are perforated with various sets of various size openings 3, the smallest openings being near the entrance and the largest near the exit. Each set of a particular size openings covers a short section of the drum and affords communication between the interior of the drum and a particular hopper 4, 5, 6, 7, 8. The

first set of openings, the ones communicating with the hopper 4 are of such a large size that about half of the bulbs to be graded will pass therethrough and into the hopper 4. From this hopper 4 the bulbs will pass down a chute 9 and into another drum HI similar to the first drum I. In the drum l the remaining half of the bulbs, that is the larger bulbs, are graded into the vari ous sizes for which the groups of openings and hoppers have been. designed to separate them into, while in the drum Ill the smaller bulbs, those constituting the half removed from the drum I through the hopper 4, are graded into the various sizes for which the groups of open ings and hoppers associated with this second drum Ill, have been designed to separate them into.

In Figure 2 is shown a view of a section on the line 2-2 of Figure 1. This figure shows more in detail the construction of the perforations in the drums and the toothed wheel II which dislodges objects that may become lodged in the perforations.

Figure 3 is an enlargement of a portion of Figure 2 along the line 33. The construction and operation of the dislodging wheel and the drum is such that the perforations in the drums are arranged in rows forming circles, and are evenly spaced apart around the drum, and the teeth I 2 on the wheel have the same pitch as these perforations so that when the wheel is placed against the outside of the drum and the drum is rotated the teeth will enter the perforations and the drum and wheel will rotate together. Any bulb that may have become lodged in a perforation will be pushed thereout and back into the interior of the drum. The wheel is placed below the center of the drum and above the angle of repose of the bulbs on the side wall of the drum. Thus, when a bulb is dislodged it will not have far to slide along the wall of the drum before it comes to rest. This prevents injury to the bulb such as it would receive if it were allowed to ride up near the top of the drum before it was dislodged. The inner surfaces of the drum may be lined with a thin sheet I3 of resilient material such as rubber. This lining may even cover the sides of the perforations. This rubber may be cemented to the drum from a sheet, or it may be sprayed thereon. This resilient material prevents injury to the bulbs as they pass through the drum.

As will be seen in detail in Figure 3, the perforations are tapered both in the direction of travel therethrough of the bulbs and in the opposite direction. That is, the openings are tapered from both sides of the drum. The taper M on the inside is for the purpose of causing a bulb, such as an iris bulb, which is of-a flattened ellipsoidal shape, to orientate with its longitudinal axis incident with the axis of an opening. If the opening is not tapered the bulbs tend to lie across the opening and to pass over it even if the opening is of a size which would pass therethrough the bulb if it were presented end on. The included angle of the taper may vary between thirty and ninety degrees. The inner taper [4 has been shown as straight sided. These sides may be opposed, that is straight or concave inwardly, but they would be inoperative if convex, that is if the tapered opening were to be cupshaped. If the opening were cup shaped, an elongated object would slide down the side of the cup and present its major axis across the opening, thus blocking it. The use of opposed walls prevents this from happening. The taper l5 on the outside is for the purpose of allowing the proper operation of the teeth on the wheel. This is analogous to the shaping of interacting gear teeth. The central part of the opening is formed as a cylindrical section !6 to add strength to the opening and to prevent chipping thereof as would be the case if there were only a thin edge.

The operation of the device is as follows:

Quantities of bulbs which have various sizes are placed on the chute 2 down which they pass into the drum drum gently rolls the bulbs and passes them along Rotation and inclination of the the drum. The surfaces of the drum are cushioned by the rubber coating l3. About half of the bulbs will pass through the perforations in the first section and into the hopper 4. This half is made up of the smaller bulbs. The remaining bulbs will pass along the drum. The smallest of these will pass into the hopper 5, and so on along the drum. The largest bulbs pass out of the end of the drum into the end hopper 8. The bulbs in the first hopper 4 pass down the chute 9 and into the second drum l0. Here they are separated and graded in the same manner as in the first drum I, as the drums are similar in construction except for the size of the perforations. If desired, more than one preliminary rough separation, or subsequent rough separations may be made. The toothed wheel II will be revolved by the drum or it may be separately driven, and the teeth will enter the perforations and dislodge any bulbs that may be therein. These bulbs will slide back down the wall and into the ungraded mass where they will be carried along until they come to an appropriate size opening. As a bulb comes to an opening it tips down into it and hence orientates itself with its longitudinal axis coincident with the axis of the opening. This gives a grading dependent upon the maximum minor diameter of the bulb and not upon its length or minimum diameter.

Having thus described an embodiment of my invention, I claim:

1. A grader for bulbs having flattened ellipsoidal shapes, comprising: a perforated drum, means for rotating said drum, and a toothed wheel arranged adjacent the exterior wall of said drum and so placed and constructed that the teeth thereof will enter into the perforations in said drum and release any object that may become lodged therein; said perforations tapering inwardly from both sides of the drum whereby upon movement of a bulb into a tapered perforation the bulb will be orientated with its major aXis coincident with the axis of the perforation and the inside taper being circular and conical.

2.'A grader for bulbs having flattened ellipsoidal shapes, comprising: a perforated drum, means for rotating said drum, and a toothed wheel arranged adjacent the exterior wall of said drum; said perforations and said wheel being so arranged that as said drum and Wheel are rotated the teeth of said wheel will enter into the perforations in said drum and release any object that may become lodged in one of said perforations", and said perforations tapering in from both sides of the drum.

VICTOR LEE PARKER. 

